automatic vent damper . The typical automatic vent damper is an electrically controlled flap that sits in the vent connector, just downstream (after) of the draft hood (draft diverter). It's just a fancy sock to stop air leaking up the chimney when the furnace is off. There are also heat activated vent dampers, but these are less common.
The immune system is a system of many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.he main response of the immune system to tumors is to destroy the abnormal cells using killer T cells, sometimes with the assistance of helper T cells. Tumor antigens are presented on MHC class I molecules in a similar way to viral antigens. This allows killer T cells to recognize the tumor cell as abnormal.
The human body contains roughly 5,000,000 hair follicles. The function of each hair follicle is to produce a hair shaft. The function of human hair depends on the part of the body from which it grows. Human hair performs several functions. It protects the skin from environmental influences. It responds to external input and translates this information into neurological impulses that are interpreted as sensory stimuli by the brain. Scalp hair is also the only part of the human body that can be readily and consciously modified to change an individual's external appearance.